Mesenchymal Neoplasms and Primary Lymphomas of the Breast

To assess the importance of various risk factors for breast cancer in women with benign proliferative breast lesions, we reevaluated 10,366 consecutive breast biopsies performed in women who had presented at three Nashville hospitals. The median duration of follow-up was 17 years for 3303 women, 1925 of whom had proliferative disease. This sample contained 84.4 per cent of the patients originally selected for follow-up. Women having proliferative disease without atypical hyperplasia had a risk of cancer that was 1.9 times the risk in women with nonproliferative lesions (95 per cent confidence interval, 1.2 to 2.9). The risk in women with atypical hyperplasia (atypia) was 5.3 times that in women with nonproliferative lesions (95 per cent confidence interval, 3.1 to 8.8). A family history of breast cancer had little effect on the risk in women with nonproliferative lesions. However, the risk in women with atypia and a family history of breast cancer was 11 times that in women who had nonproliferative lesions without a family history (95 per cent confidence interval, 5.5 to 24). Calcification elevated the cancer risk in patients with proliferative disease. Although cysts alone did not substantially elevate the risk, women with both cysts and a family history of breast cancer had a risk 2.7 times higher than that for women without either of these risk factors (95 per cent confidence interval, 1.5 to 4.6). This study demonstrates that the majority of women (70 per cent) who undergo breast biopsy for benign disease are not at increased risk of cancer. However, patients with a clinically meaningful elevation in cancer risk can be identified on the basis of atypical hyperplasia and a family history of breast cancer.

Benign breast disease is an important risk factor for breast cancer. We studied a large group of women with benign breast disease to obtain reliable estimates of this risk. We identified all women who received a diagnosis of benign breast disease at the Mayo Clinic between 1967 and 1991. Breast-cancer events were obtained from medical records and questionnaires. To estimate relative risks, we compared the number of observed breast cancers with the number expected on the basis of the rates of breast cancer in the Iowa Surveillance, Epidemiology, and End Results registry. We followed 9087 women for a median of 15 years. The histologic findings were nonproliferative lesions in 67 percent of women, proliferative lesions without atypia in 30 percent, and atypical hyperplasia in 4 percent. To date, 707 breast cancers have developed. The relative risk of breast cancer for the cohort was 1.56 (95 percent confidence interval, 1.45 to 1.68), and this increased risk persisted for at least 25 years after biopsy. The relative risk associated with atypia was 4.24 (95 percent confidence interval, 3.26 to 5.41), as compared with a relative risk of 1.88 (95 percent confidence interval, 1.66 to 2.12) for proliferative changes without atypia and of 1.27 (95 percent confidence interval, 1.15 to 1.41) for nonproliferative lesions. The strength of the family history of breast cancer, available for 4808 women, was a risk factor that was independent of histologic findings. No increased risk was found among women with no family history and nonproliferative findings. In the first 10 years after the initial biopsy, an excess of cancers occurred in the same breast, especially in women with atypia. Risk factors for breast cancer after the diagnosis of benign breast disease include the histologic classification of a benign breast lesion and a family history of breast cancer.

The study addresses the controversial prognostic and therapeutic aspects of phyllodes tumor of the breast. Records of 170 women with phyllodes tumor of the breast were reviewed. On the basis of the criteria proposed by Azzopardi and Salvadori et al., including estimation of tumor margin, growth of the connective tissue component, mitoses, and cellular atypia, the entire series was divided into three histotypes of phyllodes tumor, i.e., benign (92 cases, 54.1%), borderline (19 cases, 11.2%), and malignant (59 cases, 34.7%). Ninety-eight patients (57.6%) were treated by wide local excision (79 benign, 15 borderline, and 4 malignant), 43 (25.3%) by simple mastectomy (13 benign, 4 borderline, and 26 malignant), and 29 (17.1%) by radical mastectomy (all malignant). Of the 170 treated patients, 141 (82.9%) survived 5 years without evidence of disease. In the Cox multivariate analysis the histotype of the tumor was the only independent prognostic factor: 5-year NED survival was observed in 95.7% of the patients with benign phyllodes tumor, 73.7% with borderline phyllodes tumor, and 66.1% with malignant phyllodes tumor. After a wide local excision 98.7% of the patients with benign tumor, and 80% with borderline tumor, were cured. Local recurrence was found in 14 patients (8.2%) (4 benign, 3 borderline, and 7 malignant); 10 of these underwent reoperation (7 wide local excision, 3 radical mastectomy) and survived 5 years NED. The histotype of phyllodes tumor (benign, borderline, and malignant), assessed on the basis of the criteria proposed by Azzopardi and Salvadori et al., was the only prognostic factor in our group of patients. Based on the data from literature and our own observations, we observed that a wide local excision, with an adequate margin of normal breast tissue, is the preferred initial therapy for phyllodes tumor of the breast.